The following description is provided to assist the understanding of the reader. None of the information provided or references cited is admitted to be prior art. Some magnetometers use magneto-optical defect center materials to determine a magnetic field. Such magnetometers can apply a magnetic bias to the magneto-optical defect center materials. There is a desire for improving and optimizing a method for applying the magnetic bias to the magneto-optical defect center materials while maintaining functionality of the magnetometer and/or adjustability of the magnetometer.